00:01
Can we have this circuit? the first thing i want to do is i want to get it and get an equivalent resistance.
00:08
Make life a lot easier.
00:11
So there's a couple steps to do that.
00:16
So first of all, this 10k and the 30k on the bottom are in series.
00:22
So we can replace it by a series combination of 40k.
00:28
And i'm also going to replace the batteries because they're in series by a single one that's 48.
00:38
Okay.
00:41
Then the two resistors on the right are in parallel, so they can be replaced by a parallel combination.
00:51
It comes out to be 8k because 110s plus 140th is 540th, which turns out to be 8.
01:06
Okay.
01:06
And then finally, the two resistors that are left are in series.
01:18
So they have total 38k because they're in series.
01:27
Okay.
01:29
So the time constant is r times c, so that's 38k times 100 millifreds, which by the way is an enormous amount of capacitance...